1. Field of the Invention
The present invention relates to door controls and more particularly to a control for holding a door open for a predetermined period of time.
2. Description of the Prior Art
Manually operated doors for commercial buildings conventionally employ closure devices which return the door to closed position after the traffic has passed therethrough. The same type of operation is conventional for power operated doors which in some cases employ return springs for closing a door after traffic has cleared.
Since such doors are normally closed and are yieldably retained in such position, to hold the door open requires that the person passing therethrough do this manually. To accommodate passage of personnel with hand carts and material handling vehicles, it is usually necessary for the door either to be propped open, another person to hold it until the doorway is cleared, or the door be equipped with a fully automatic powered system. The fully automatic, powered system is often cost prohibitive to the door owner. This invention offers an alternative in the form of a semi-automatic door. This door-holding operation involves an element of inconvenience and attendant expense in the form of personnel time which this present invention seeks to avoid.